Comparative analysis of particulate matter emissions and health risks from biomass and LPG cooking fuels

Indoor air pollution from biomass fuel combustion remains a major health concern in developing countries, particularly affecting women and children. This study investigates emissions of size-fractionated particulate matter (PM1, PM2.5, PM10) from five commonly used cooking fuels i.e., wood, cow dung, crop residue, coal, and liquefied petroleum gas (LPG) under controlled indoor conditions. Biomass fuels emitted 1.4–1.8 times higher PM2.5 and PM10 concentrations than LPG, with cow dung showing the highest levels (PM10 = 757 μg/m3, PM2.5 = 701 μg/m3, PM1 = 638 μg/m3). Exposure assessment revealed that women and children received greater particulate deposition, with coarse particles settling mainly in the head region and fine particles in the alveolar region. Non-carcinogenic risk analysis indicated hazard quotient (HQ) values above unity for all biomass fuels, implying potential adverse health impacts, especially among children and infants. Elemental characterization identified Na, Al, Si, and K as dominant elements, while toxic Ba was detected in all fuels except LPG. Morphological analysis showed predominantly spherical and irregular particles. Overall, the findings highlight that biomass fuels significantly elevate indoor PM levels and associated health risks, underscoring the urgent need for cleaner cooking technologies, better ventilation, and policy measures to protect exposed populations.